Full utilization of silt density index (SDI) measurements for seawater pre-treatment

Handle URI:
http://hdl.handle.net/10754/562225
Title:
Full utilization of silt density index (SDI) measurements for seawater pre-treatment
Authors:
Wei, Chunhai; Laborie, Stéphanie; Ben Aïm, Roger M.; Amy, Gary L.
Abstract:
In order to clarify the fouling mechanism during silt density index (SDI) measurements of seawater in the seawater reverse osmosis (SWRO) desalination process, 11 runs were conducted under constant-pressure (207kPa) dead-end filtration mode according to the standard protocol for SDI measurement, in which two kinds of 0.45μm membranes of different material and seawater samples from the Mediterranean including raw seawater and seawater pre-treated by coagulation followed by sand filtration (CSF) and coagulation followed by microfiltration (CMF) technologies were tested. Fouling mechanisms based on the constant-pressure filtration equation were fully analyzed. For all runs, only t/(V/A)∼t showed very good linearity (correlation coefficient R 2>0.99) since the first moment of the filtration, indicating that standard blocking rather than cake filtration was the dominant fouling mechanism during the entire filtration process. The very low concentration of suspended solids rejected by MF of 0.45μm in seawater was the main reason why a cake layer was not formed. High turbidity removal during filtration indicated that organic colloids retained on and/or adsorbed in membrane pores governed the filtration process (i.e., standard blocking) due to the important contribution of organic substances to seawater turbidity in this study. Therefore the standard blocking coefficient k s, i.e., the slope of t/(V/A)∼t, could be used as a good fouling index for seawater because it showed good linearity with feed seawater turbidity. The correlation of SDI with k s and feed seawater quality indicated that SDI could be reliably used for seawater with low fouling potential (SDI 15min<5) like pre-treated seawater in this study. From both k s and SDI, the order of fouling potential was raw seawater>seawater pre-treated by CSF>seawater pre-treated by CMF, indicating the better performance of CMF than CSF. © 2012 Elsevier B.V.
KAUST Department:
Water Desalination and Reuse Research Center (WDRC); Water Desalination and Reuse Research Center; Biological and Environmental Sciences and Engineering (BESE) Division
Publisher:
Elsevier BV
Journal:
Journal of Membrane Science
Issue Date:
Jul-2012
DOI:
10.1016/j.memsci.2012.03.010
Type:
Article
ISSN:
03767388
Sponsors:
This work has been financed by European Union within the MEDINA (Membrane-Based Desalination: An Integrated Approach) Project (no. 036997). The authors also gratefully acknowledge Veolia Water for sampling seawater.
Appears in Collections:
Articles; Water Desalination and Reuse Research Center (WDRC); Biological and Environmental Sciences and Engineering (BESE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorWei, Chunhaien
dc.contributor.authorLaborie, Stéphanieen
dc.contributor.authorBen Aïm, Roger M.en
dc.contributor.authorAmy, Gary L.en
dc.date.accessioned2015-08-03T09:57:05Zen
dc.date.available2015-08-03T09:57:05Zen
dc.date.issued2012-07en
dc.identifier.issn03767388en
dc.identifier.doi10.1016/j.memsci.2012.03.010en
dc.identifier.urihttp://hdl.handle.net/10754/562225en
dc.description.abstractIn order to clarify the fouling mechanism during silt density index (SDI) measurements of seawater in the seawater reverse osmosis (SWRO) desalination process, 11 runs were conducted under constant-pressure (207kPa) dead-end filtration mode according to the standard protocol for SDI measurement, in which two kinds of 0.45μm membranes of different material and seawater samples from the Mediterranean including raw seawater and seawater pre-treated by coagulation followed by sand filtration (CSF) and coagulation followed by microfiltration (CMF) technologies were tested. Fouling mechanisms based on the constant-pressure filtration equation were fully analyzed. For all runs, only t/(V/A)∼t showed very good linearity (correlation coefficient R 2>0.99) since the first moment of the filtration, indicating that standard blocking rather than cake filtration was the dominant fouling mechanism during the entire filtration process. The very low concentration of suspended solids rejected by MF of 0.45μm in seawater was the main reason why a cake layer was not formed. High turbidity removal during filtration indicated that organic colloids retained on and/or adsorbed in membrane pores governed the filtration process (i.e., standard blocking) due to the important contribution of organic substances to seawater turbidity in this study. Therefore the standard blocking coefficient k s, i.e., the slope of t/(V/A)∼t, could be used as a good fouling index for seawater because it showed good linearity with feed seawater turbidity. The correlation of SDI with k s and feed seawater quality indicated that SDI could be reliably used for seawater with low fouling potential (SDI 15min<5) like pre-treated seawater in this study. From both k s and SDI, the order of fouling potential was raw seawater>seawater pre-treated by CSF>seawater pre-treated by CMF, indicating the better performance of CMF than CSF. © 2012 Elsevier B.V.en
dc.description.sponsorshipThis work has been financed by European Union within the MEDINA (Membrane-Based Desalination: An Integrated Approach) Project (no. 036997). The authors also gratefully acknowledge Veolia Water for sampling seawater.en
dc.publisherElsevier BVen
dc.subjectFouling potentialen
dc.subjectOrganic colloidsen
dc.subjectSDIen
dc.subjectSeawateren
dc.subjectStandard blockingen
dc.titleFull utilization of silt density index (SDI) measurements for seawater pre-treatmenten
dc.typeArticleen
dc.contributor.departmentWater Desalination and Reuse Research Center (WDRC)en
dc.contributor.departmentWater Desalination and Reuse Research Centeren
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
dc.identifier.journalJournal of Membrane Scienceen
dc.contributor.institutionInst Natl Sci Appl Toulouse, Lab Ingn Syst Biol & Procedes, Dept Genie Procedes & Environm, F-31077 Toulouse 4, Franceen
dc.contributor.institutionInst Filtrat & Separat Tech IFTS, F-47510 Foulayronnes, Franceen
kaust.authorWei, Chunhaien
kaust.authorAmy, Gary L.en
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